Similar products are commercially manufactured following usually a number of thermal processing system(s). These processes include drum drying, extrusion technology, toasting/roasting, gun puffing etc. where the products attain a low moisture content for safe storage and are easily digested.
Through years of efforts accompanied by changes and improvements, traditional food products became a matter of proud. Traditional food products are preferred by most of the people because of product familiarity, known taste, attractive texture, and in several cases it is just a traditional item.
However, traditional foods can be used as a ‘carrier of nutritional ingredients’ provided they do not alter or affect the popular acceptance of such products. In Oriental countries, the semolina of wheat is used in preparing a sweet product like halwa (sweet dish) or kesari bhath or sweet soji (savory dishes) and a salty product like upmav (breakfast savory dish), whereas rice flour is used for making gruel or porridge-like products.
Porridge is also popular traditional product in the continents of Europe and America. Corn or maize is popular in several continents particularly Europe, Africa and America continents for making a large number of food products including snacks and different convenience foods. Corn is also been cultivated to a certain extent in India but is still considered to be a low-cost cereal. Except for corn oil, the other ingredients derived from it, such as, corn grit, flour and powder are typically underutilized low-cost material that are not only available in abundant but also cheaper compared to other popular cereals such as rice and wheat.
Soybean or soyabean is a commodity known for its high protein content and other health benefits. On the other hand, defatted soybean flour, obtained after the extraction of valuable oil, is an under utilised low-cost raw material though its protein content is nearly half of the ingredient itself. Though several researchers have focussed on the use of this high-protein plant source ingredient, it is still a neglected item but possesses a promising future. A few products, made from soy flour, that have some popularity include textured soy protein by employing extrusion technology, traditional Asian product tofu or soybean curd by using fermentation, and several fortified foods like bread, biscuit etc.
Hence, there is a need for developing high-protein food by using commonly available ingredients that will not only be cost-effective but also provide convenience, possibly in a ready-to-cook form, to the consumers such that it can be used in nutritional intervention programme and can be consumed as a health food.
Several approaches for the utilization of soybean and soybean fractions are possible. Protein based foods having low cost of production are often formulated using defatted oilseeds (such as soybean) and a cereal.
Extrusion markedly improves the nutritional availability of the ingredients of the product by inactivating the anti-nutritional factors and facilitating easier digestibility (Furuichi, Y., Kubota, Y., Sugiura, Y., Umekawa, H., Takahashi, T and Kouno, S. 1989. Effects of low-moisture extrusion cooking on the chemical composition and nutritional value of whole soybeans. Journal of Japanese Society of Nutrition and Food Science 42(2), 165-172; Guzman, G. J., Murphy, P. A. and Johnson, L. A. 1989. Properties of soybean-corn mixtures processed by low-cost extrusion. Journal of Food Science, 54(6), 1590-1593) which depends on the extrusion conditions (Peters, J., and Czukor, B. 1989. Investigation of the effects of extrusion cooking on antinutritional factors in soybeans employing response surface analysis. II. Effect of extrusion cooking on urease and hemagglutinin activity. Nahrung. 33(8), 729-736). Reference may also be made to Hait (1978, U.S. Pat. No. 4,126,705), and Mickle et al. (1980, U.S. Pat. No. 4,183,966) who have reported processes for manufacturing protein snack foods. The later process also mentioned the application of deep-fat frying to make the snack product.
Reference may also be made on extrusion processes to develop puffed foods having a soft mouth feel when the raw material is egg shell or bone powder, and a predominantly starchy or proteinaceous food material (Kurokawa et al., 1990, U.S. Pat. No. 4,891,238), and also in another example of an extrusion snack (Sadel and Sangiovanni, 1988, U.S. Pat. No. 4,778,690) employing a cereal (corn, rice or wheat) and post-extrusion cooking in oil.
The drawbacks of these processes lie in cooking in oil at the later stages which increase cost of product, reduce shelf-life, and above all, the high oil content in the product may not be suitable for its use as a health food where low-fat/oil content is usually desirable.
Reference may be made to the development of textured vegetable protein using extrusion technology (J. Bergman, Process for blended food products, U.S. Pat. No. 3,959,500 in 1976). The product mentioned here (textured vegetable protein) and the present product (coated cereal food) are different in nature and their process of preparation are also different.
Legume chip was developed by K. Samuel and others in 1978 (Preparation of legume chips, U.S. Pat. No. 4,084,016) by first mixing the acidified legume powder with the regular legume powder followed by adding water to the mix to form a paste and then extruding into thin sheets; later, bite-size pieces were cut from thin sheets and are par-fried in edible oil to get legume chip snacks. It is necessary to mention here that the drawbacks of using extrusion technology lie in use of sophisticated equipment. In addition, frying leads to high fat content in the product, which may not be considered good from the health point of view. Further, the cost of the finished product increases whereas shelf life of the product decreases.
Reference may be made U.S. Pat. No. 6,033,696 (2000) wherein claims have been made for a process for coating of extrusion cooked cereals with a sweet tasting slurry. However, the product is for a snack application in which the base is different from the present study. Moreover, the product contains 3-5% of vegetable fat, which is a disadvantage for the product. Further, the ingredients for coating used include fruit/vegetable puree/concentrate, whole milk powder, etc., which are entirely different from the present application.
Fermentation of the soybean is an another approach to develop soybean based food products. Reference may be made to Japanese patent JP004818A2 (K. Konishi, 2000, Ready-to-eat food admixed with soybean-curd refuse and fermented soybean and its production) wherein a claim has been made to develop a soybean-paste soup-like ready-to-eat food in which soybean curd refuse is heated at high temperature followed by fermentation. In an another approach employing fermentation, W. Sugui and S. Toshiyki in 1999 (Fermented soybean having no spornioderm and its production, Japanese patent 11113521A2), the fermented soybeans were modified by heating followed by effusing of sugar component. The drawback of these processes is the use of a high moisture fermentation process where energy-expensive drying process is to be applied to get the final product.
Reference may be made to Japanese patent JP3015356A2 (M. S. K. K. Ishiyama, 1991, Soybean food) wherein claim has been made to obtain a soybean food having a new kind of taste and original flavor. The drawback of this process is use of a high moisture fermentation process where energy expensive drying process is to be applied to get the final dried product.
Reference may be made to U.S. Pat. No. 5,437,885 (Edmund and others, 1995, Method of making a non-porous vegetable protein fiber product) wherein claim has been made for processing a dehulled, defatted oilseed protein, e.g., soybean meal, to produce non-porous meat like fibers, comprises preparing oilseed protein source and water like mixture, extruding the mixture, coating the extruded mixture with an edible oil or fat and then further extruding the oil- or fat-coated fibers. The drawback of this process lie in use of sophisticated costly equipment like extruder, and practicing the extrusion processing two times. Further, the use of oil or fat increases the fat content of the product which may not be a desired condition for producing a health food because the latter foods usually is based on low-calorie/low-fat principle. In addition, use of fat or oil reduces the shelf life of the product as the possibility of rancidity enhances.
Reference may be made to U.S. Pat. No. 3,649,293R (A. Hoer and F. E. Calvert, 1972, A method for producing a bay protein product) in which de-fatted soybean materials were made into an aqueous slurry in a selected range of pH and later precipitating the protein on and into the surfaces of the cellular portion of the soybean material, separating this protein, coated solid material from the liquid carbohydrate portion, forming a second aqueous slurry. Later this slurry was instantaneously heated at a very high temperature under pressure followed by drying the protein coated cellular material. The drawback of this process lie in a number of processing systems in addition to high energy cost for drying aqueous slurry.
Reference may be made to R. D. Olson and R. H. Eifler in 1976 (Breakfast cereal process and product, U.S. Pat. No. 3,976,793) who claimed a process for sugar coated ready-to-eat breakfast cereal flake composed principally of oat and soyflour. It was claimed that enhanced crispness retention and sweetness impact occurs when dilute sweetening syrup was impregnated on the flake surface, which is crystallized thereon so as not to be grossly visible. The process for breakfast cereal is entirely different from the present process. In addition, the claimed process is on a ready-to-eat product and coating on such bigger piece is much easier than coating on grits which are too small and difficult to coat.
Reference may be made to U.S. Pat. No. 4,119,734 (A. Spiel, High protein rice mixture 1978) wherein the particulate soy protein particles were used along with rice grains to produce protein-rice food products. The developed product resembles that of rice. The drawback of this process is the use of high-pressure treatment, which makes the process a batch one.
Reference may be made to U.S. Pat. No. 4,044,157 (M. Wilding, 1977. Process for preparing expanded soybean granules) claimed a process in which a protein food product having an expanded, elongated cellular structure similar to meat is prepared by forming a dough with seed flour. The method consists of heating the dough under pressure followed by extrusion. The drawback of this process lie in use of sophisticated equipment such as extruder and use of high pressure which may be detrimental to the food product. In addition, this type of process is usually a batch processing system and is also a costly one.
Reference may be made to U.S. Pat. No. 5,612,074 (R. L. Leach, 1997. Nutrient fortified food bar) wherein claim was made for a process on nutrient fortified non-cooked food bar having dietary fiber, non-animal protein etc. that has been given a shape of a food bar. The drawback of this process is that the product is an uncooked food with low protein content such that it can not be categorised into protein-rich convenience foods.
Reference may be made to U.S. Pat. No. 3,723,407 (D. M. Miller and M. D. Wilding, Method of preparing vegetable protein concentrates, 1973) wherein vegetable protein concentrates of high viscosity are obtained by using denatured, defatted, vegetable protein source material with an aqueous system, acidifying the said system and subjecting the material to centrifugal speeds and differential pressure effects. The drawback of the process is the maintenance of the very low pH (such as 3.0) such that there is a chance of alteration in the nutritional status especially the basic amino acids in protein molecules and disruption of natural cell structure of the protein bodies.
The reference may be made to U.S. Pat. No. 3,911,142 (1975), wherein a process for preparing a protein snack food was described. A ready-to-eat snack was made from soy protein and potato flakes. After mixing these ingredients with wheat flour to form a mass, it was shaped into pieces followed by baking or frying to produce the desired product. However, it is essentially a wheat product of cookie type and the sequences of processing steps differ from the one presented.
The reference may be made to U.S. Pat. No. 5,731,019 (1998) wherein a coated food product containing a non-starch coating composition had been disclosed. The composition includes oligosaccharides (2-10%), soluble protein (3-12%, vegetable oil (10-60%), emulsion (0-5%) and water (13-85%). The claims are that this coating composition does not contain starch and can be used to from the crumb (one or more layers). The drawback of this composition lie in medium to higher level of added fat and the product is meant for crumb that is different from the present application.
The reference may be made to U.S. Pat. No. 5,972,399 (1999) wherein claims have been made for a process for a ready-to-cook product made up of a cooked and hydrated carbohydrate core, and a cation reduces the core's glycemic response. In a similar manner, U.S. Pat. No. 5,795,606 (1998) claims for a method comprising boiling in an aqueous medium containing cross-linking cation to develop a ready-to-eat food. The disadvantage of this claim is that the product is meant for persons with diabetic problems. In addition, hydrated carbohydrate core, and a cation cross-linked polysccharide coating were used that are different from the present application.
Reference may be made U.S. Pat. No. 3,952,110 (1976) in which claims have made for a dry mix for coating of foods where spices and meats have been used while maintaining the pH between 5.2 and 6.8. The application of this product is different from the present claim. Moreover, maintaining a specific range of pH means adding water to the system which is a drawback for the claimed process.
Reference may be made to U.S. Pat. No. 5,595,777 (1997) in which a claim has been made for a preparing a gel to be coated on food products for developing breaded substances. However, the product as well as the batter constituents is entirely different from the present application.
Reference may be made to U.S. Pat. No. 5,753,286 (1998) wherein claims have been made for the development of a crunchy coating and a process for preparing coated foods. The coating includes a pre-dust that adheres to the water containing gel batter. However, the application of the product as well as the method of application is different from the present application.
It is, thus, concluded that there is a need for high-protein low-cost convenience foods that can be manufactured using simple systems and commonly available ingredients without sacrificing the attractive taste and nutritional benefits such that the same may be used as a health food for several purposes including nutritional intervention programme.
The criterion for such products includes safety, affordable price, acceptable taste, considerable shelf life, attractive texture, and undoubtedly, the proper nutritional balance. In some cases, the protein and/or energy content and convenience in use become critical factors if these foods are considered as a health food or as a food to be used for nutritional intervention programmes.
The objects the present invention thus relates to cereal food product and a process for high protein coated cereal food, which obviates the drawbacks as detailed earlier.